Nanoparticle-textured surfaces and related methods for selective adhesion, sensing and separation

Abstract

Textured heterogeneous surfaces and related articles as can be used in conjunction with methods for selective sensing and/or separation. When used for selective particle separation such a system can comprise a heterogeneous surface comprising a surface member and a plurality of components extending therefrom, such components spaced about and having a surface density, with heterogeneity comprising different interactions of the surface member and of the extended components with a particle exposed thereto. Various surface heterogeneities and different interactions can be utilized. However, in certain embodiments, competing electrostatic interactions, or a combination of electrostatic and non-electrostatic interactions, with a particle can be utilized. Such a system can utilize a surface member having a charge difference with respect to the components extending therefrom.

1. A method of selective particle separation, said method comprising: providing a heterogeneous surface comprising a surface member and a plurality of components coupled thereto and extending therefrom, said components spaced about said surface member and having a density thereon, said surface heterogeneity providing different interactions of said surface member and said spaced components with a particle exposed thereto; exposing a particle mixture to said heterogeneous surface; and separating particles from said mixture with said heterogeneous surface, said separation selective for a said particle. 
     
     
       2. The method of  claim 1  wherein said particles are dimensioned from about 30 nm to about 20 μm. 
     
     
       3. The method of  claim 1  wherein said heterogeneity comprises at least one of different electrostatic interactions and van der Waals interactions with said particle. 
     
     
       4. The method of  claim 3  wherein each of said surface member and said components has a net charge at least partially sufficient for selective particle separation. 
     
     
       5. The method of  claim 3  wherein said components have a surface charge density at least partially sufficient for selective particle separation. 
     
     
       6. The method of  claim 1  wherein each said component comprises a cross-sectional dimension up to about 50 nm, said dimension providing component extension beyond said surface member. 
     
     
       7. The method of  claim 6  wherein said components comprise an average spatial density, said spatial density at least partially sufficient for selective particle separation from said mixture. 
     
     
       8. The method of  claim 7  wherein at least one of rate of particle adhesion and strength of particle adhesion varies with spatial density. 
     
     
       9. The method of  claim 6  wherein a said component comprises a nanoparticulate composition comprising a metal core and a shell thereabout, said component cross-sectional dimension comprising said core/shell diameter. 
     
     
       10. The method of  claim 9  wherein said core comprises a precious metal, and said shell comprises ligands selected from cationic and anionic ligands. 
     
     
       11. The method of  claim 10  wherein said nanoparticulate composition comprises cationic ligands, said component comprising a net positive charge, and said surface member comprises a net negative charge. 
     
     
       12. The method of  claim 1  wherein said particles are collected from said surface, for exposure to another particle mixture. 
     
     
       13. The method of  claim 1 , wherein the plurality of components extends by a distance of at least a length of a repulsive background field of the surface. 
     
     
       14. The method of  claim 13 , wherein the length of the repulsive background field of the surface is a Debye length.